Entertainment Weekly has on their website a photo show of what they call "20 Perfect Movie Endings." Some predictable (Vertigo), some less predictable (Rushmore). If you don't feel like clicking & reading, here they are (I don't think they're ranked):
The Sixth Sense
The Seventh Seal
Gone With the Wind
The 400 Blows
About A Boy
One Flew Over the Cuckoo's Nest
Thoughts? Agreements? Omissions?